Perform system configuration; Security Technical Implementation Guide (STIG) compliance and security hardening; account, privilege, and access management; vulnerability scanning and remediation; configuration and change management; backup and recovery; audit-log review; incident-response support; and maintenance of cybersecurity and system documentation. Experience with virtualization technologies, containerized applications, GPU-accelerated computing resources, and modern system monitoring tools; familiarity with Automation/AI (A/AI), Modeling and Simulation (ModSim), or large language model (LLM) systems in air-gapped environments.